Through Wafer Vias for RF Interconnection by Molten Solder Ejection Method

Abstract

Through wafer vias plugged with solder for RF interconnection are described. Molten solder ejection method is a maskless full-dry process and it was shown that the plugging solder was voidless and hermeticity was expected. Waveguide patterns can be formed on both sides of silicon substrates without a planarization process using a standard spin-on photoresist lithography. RF transmittance of coplanar waveguides with through wafer interconnects was measured up to 100 GHz and it agreed well with calculation.